The sum of all rational terms in the expansion of $\left( 1 + 2 ^ { 1 / 2 } + 3 ^ { 1 / 2 } \right) ^ { 6 }$ is equal to
The sum of all rational terms in the expansion of $\left( 1 + 2 ^ { 1 / 2 } + 3 ^ { 1 / 2 } \right) ^ { 6 }$ is equal to